Police in Nigeria say one of more than 200 girls kidnapped by the Islamist group Boko Haram in April has been released.

A police spokesman, Emmanuel Ojukwu said, a 20-year-old woman who was among those kidnapped five months ago, was found Wednesday in the village of Mubi in Adamawa state. The girl said she spent several days in the bush after being released by Boko Haram.

The girl's identity has not been confirmed, however, and an elder from the community of Chibok, where the girls were abducted, said the name the girl gave for herself was not on the list of kidnapped women. He said the girl had been traumatized and was unable to communicate clearly.

Nigeria's government has been criticized for its slow response to the kidnappings and failure to rescue the victims.

And false hopes have been raised before. On Tuesday, the military first issued, then retracted, a confirmation of reports that several of the girls had been released in the past few days. The reports were found to have been based on incorrect information.

On Wednesday, hundreds of Islamic extremists surrendered following recent air and ground attacks that the Nigerian military launched against Boko Haram.

One of the casualties from the attacks was Mohammed Bashir, according to the Nigerian Defense Ministry. The military has described Bashir as an imposter who portrayed Boko Haram leader Abubakar Shekau in videos published by the militants.

Nigerian military officials say Abubakar Shekau was killed in battle last year, although Boko Haram has released videos showing him this year - issuing threats, taunting Nigerian authorities and claiming responsibility for the Chibok abductions.